Usage And Dosage Of Oseltamivir

Oseltamivir phosphate can be taken with food or separately. However, for some patients, taking medicine at the same time can improve drug tolerance.
Treatment of influenza:
Treatment should begin on the first or second day (ideally within 36 hours) of the onset of influenza symptoms.
1. Dose guidance
Adults and adolescents:
The recommended oral dose of oseltamivir phosphate capsules for adults and adolescents over 13 years of age is 75 mg per time, twice daily, for 5 days.
Prevention of influenza
The recommended oral dose of oseltamivir phosphate for influenza prevention after close contact with influenza patients is 75 mg, once a day, for at least 10 days. The drug should also be started within 2 days after close contact. The recommended dose of oseltamivir phosphate for influenza prevention in influenza season is 75 mg, once a day. Some data show that the drug is safe and effective for 6 weeks. It has a preventive effect during medication.
2. Medication guidance for special population
Patients with renal insufficiency:
Influenza treatment: it is not necessary to adjust the dose for patients with creatinine clearance rate greater than 60ml/min. For those whose creatinine clearance rate is greater than 30ml/min but not greater than 60ml/min, the recommended dosage is reduced to 30mg per time, twice a day, for a total of 5 days. For those whose creatinine clearance rate is greater than 10ml/min but not greater than 30ml/min, the recommended dosage is reduced to 30mg each time, once a day, for a total of 5 days. For regular hemodialysis patients, if the flu symptoms worsen within 48 hours during the interdialysis period, the initial dose of 30mg can be given before the start of dialysis. In order to maintain the blood drug concentration at the treatment level, a dose of 30mg should be given after each dialysis. For peritoneal dialysis patients, it is recommended to give this product 30mg before dialysis, and then 30mg every day for 5 days (see [Pharmacokinetics] and [Precautions]). The pharmacokinetics of oseltamivir in patients with end-stage renal disease (i.e. creatinine clearance<10ml/min) without dialysis has not been studied. Therefore, it is not possible to provide suggestions on the dosage of this kind of patients.
Influenza prevention: it is not necessary to adjust the dose for patients with creatinine clearance rate greater than 60ml/min. For those whose creatinine clearance rate is greater than 30ml/min but not greater than 60ml/min, the recommended dosage is reduced to 30mg each time, once a day. For those whose creatinine clearance rate is greater than 10ml/min but not greater than 30ml/min, the recommended dosage is reduced to 30mg each time, once every other day. For regular hemodialysis patients, if the flu symptoms worsen within 48 hours during the interdialysis period, the initial dose of 30mg can be given before the start of dialysis. In order to maintain the blood drug concentration at the treatment level, a dose of 30mg should be given after every two dialysis sessions. For peritoneal dialysis patients, it is recommended to give this product 30mg before dialysis, and then 30mg every day for 7 days (see [Pharmacokinetics] and [Precautions]). The pharmacokinetics of oseltamivir in patients with end-stage renal disease (i.e. creatinine clearance<10ml/min) without dialysis has not been studied. Therefore, it is not possible to provide suggestions on the dosage of this kind of patients.
Patients with liver insufficiency:
The dose used for the treatment and prevention of influenza in patients with mild and moderate hepatic insufficiency does not need to be adjusted (see [Pharmacokinetics]). The safety and pharmacokinetics of this product for patients with severe liver insufficiency have not been studied.